tools: reduce source tarball compression in CI

Make source-tarball gzip compression configurable, keeping level 9 as
the default. Use level 6 in build-tarball and test-shared to reduce
tarball creation time with a small increase in archive size.

Refs: #66228 (comment)

Assisted-by: Codex
Signed-off-by: inoway46 <inoueyuya416@gmail.com>

Author: inoway46

.github/workflows/build-tarball.yml

@@ -94,7 +94,7 @@ jobs:
           export DISTTYPE=nightly
           export DATESTRING=$(date "+%Y-%m-%d")
           export COMMIT=$(git rev-parse --short=10 "$GITHUB_SHA")
-          ./configure && make tar -j4 SKIP_XZ=1
+          ./configure && make tar -j4 SKIP_XZ=1 GZIP_COMPRESSION=6
       - name: Upload tarball artifact
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
         with:

.github/workflows/test-shared.yml

@@ -133,7 +133,7 @@ jobs:
         run: |
           export DATESTRING=$(date "+%Y-%m-%d")
           export COMMIT=$(git rev-parse --short=10 "$GITHUB_SHA")
-          ./configure && make tar -j4 SKIP_XZ=1 SKIP_SHARED_DEPS=1
+          ./configure && make tar -j4 SKIP_XZ=1 SKIP_SHARED_DEPS=1 GZIP_COMPRESSION=6
         env:
           DISTTYPE: nightly
 

Makefile

@@ -1113,6 +1113,7 @@ HAS_XZ ?= $(shell command -v xz > /dev/null 2>&1; [ $$? -eq 0 ] && echo 1 || ech
 SKIP_XZ ?= 0
 XZ = $(shell [ $(HAS_XZ) -eq 1 ] && [ $(SKIP_XZ) -eq 0 ] && echo 1 || echo 0)
 XZ_COMPRESSION ?= 9e
+GZIP_COMPRESSION ?= 9
 PKG=$(TARNAME).pkg
 MACOSOUTDIR=out/macos
 
@@ -1345,7 +1346,7 @@ endif
 	find $(TARNAME)/ -type l | xargs $(RM)
 	tar -cf $(TARNAME).tar $(TARNAME)
 	$(RM) -r $(TARNAME)
-	gzip -c -f -9 $(TARNAME).tar > $(TARNAME).tar.gz
+	gzip -c -f -$(GZIP_COMPRESSION) $(TARNAME).tar > $(TARNAME).tar.gz
 ifeq ($(XZ), 1)
 	xz -c -f -$(XZ_COMPRESSION) $(TARNAME).tar > $(TARNAME).tar.xz
 endif